1. Field of the Invention
The invention is directed to a method for transmitting additional information when using a method for compressing data with a prioritizing pixel transmission, wherein the data comprise individual pixel groups, with each pixel group having a position value within an image array and at least one pixel value and wherein the minimal size of the image array is defined by the height h and the width b of an image, expressed in pixels.
Most information is currently already provided in electronic form. A large number of data formats exist that are optimized and/or specified by a manufacturer for different applications. These data formats are standardized, for example, as so-called MIME types, document formats and graphic formats. Documents can be assembled from documents having different data formats, for example on a website. However, if the individual documents overlap, e.g., if a transparent text is overlaid on a picture, or if a moving display is used, then it may be difficult to find an optimal combination that achieves the highest compression rates, because, for example, the various documents are independent of each other.
2. Description of the Related Art
A basis of the present invention are methods for compressing and decompressing image or video data through prioritized pixel transmission, are disclosed, for example, in U.S. Pat. No. 7,130,347 and U.S. published application 2004/0109609. These methods process, for example, digital image data or video data consisting of an array of individual pixels, with each pixel having a time-dependent pixel value that describes color and luminance information of the pixel. According to the invention disclosed in these documents, a priority is associated with each pixel and/or with each pixel group, and the pixels are written to a priority array according to their prioritization. At each point in time, the array includes the pixel values sorted according to their prioritization. These pixels and the pixel value used for computing the prioritization are transmitted and/or stored according to the prioritization. A pixel is given a high priority, if the difference with respect to its adjacent pixels is very large. The actual pixel values are reconstructed on a display. The pixels that have not ever been transmitted are computed from the already transmitted pixel.
The entire contents of the applications U.S. Pat. No. 7,130,347 and U.S. published application 2004/0109609 are included in the present application by reference.
The methods described in U.S. Pat. No. 7,130,347 and U.S. published application 2004/0109609 for prioritizing pixel transmission have a number of advantages, for example a high compression ratio, scalability, error tolerance, etc. In the certain cases, it may be more advantageous to employ a combination of different compression methods. However, it may be a problem to optimally combine these different methods, while maintaining the basis for the compression, namely the prioritizing pixel transmission.
It is an object of the present invention to provide a method for transmitting additional information with the prioritizing pixel transmission that enables an effective compression of documents having a plurality of different document types.